Recently, there has been eagerly studied a technique of emitting fluorescence by irradiating a fluorescent material layer with exciting light emitted from an excitation light source as which a semiconductor light emitting element such as a light emitting diode (LED) or a semiconductor laser (LD; Laser Diode) serves. Typical examples of an excitation light source of a light emitting device encompass (i) an electron gun that is in widespread use for, for example, emission of cathode rays, (ii) a fluorescent lamp that emits ultraviolet rays generated by electric discharge, and (iii) the semiconductor light emitting element. In any light emitting devices, a film of a fluorescent material is ingeniously produced so that the fluorescent material can efficiently emit fluorescence from a fluorescent material layer. Patent Literatures 1 through 4 disclose examples of the light emitting device and a cathode ray tube, each of which includes such a fluorescent material layer.
Patent Literatures 1 and 2 disclose a light emitting device including a fluorescent material layer that includes (i) a light emitting element whose surface has fluorescent material particles thereon or (ii) a glass tube whose inner surface has fluorescent material particles thereon. Patent Literatures 3 and 4 disclose a cathode ray tube including a fluorescent material layer that includes a face glass or a panel substrate whose surface has fluorescent material particles thereon. Non-Patent Literature 1 discloses a technique in which a fluorescent material layer including fluorescent material particles is formed on an ITO substrate.